1. Field of the Invention
The present invention relates to a mobile terminal and, more particularly, to a method for signaling a voice calf of a mobile terminal.
2. Description of the Background Art
As a method for acquiring security of a mobile terminal, a method in which the user of a mobile terminal is authenticated when an authentication value of the mobile terminal and that of a radio network are identical by using an authentication key (A-key) is typically used. However, this method has a problem in that when an ESN (Electronic Serial Number), a MIN (Mobile Identification Number), or the authentication key (A-key) value information of the user is exposed, the authentication value of the terminal may be easily copied, so the security of the mobile terminal cannot be permanently guaranteed.
In the electronic banking field, in most cases, a method of authenticating the user by using a random number table card is used, which, however, has a limitation in that the random number table card is generated within a certain rule. In an effort to solve the problem, recently, a temporary password called a one time pass (OTP) is used. Namely, the terminal transfers an OTP to an Internet application server through the wireless Internet to perform user authentication. In this case, however, in order to transfer the OTP through the wireless Internet, a packet data call with a service option 33 is required but, in case of a general voice call, there is no signaling method for processing the authentication of the OTP transfer method.
Namely, in order to strengthen security for a voice call of the mobile terminal, a signaling method for performing the OTP authentication according to the voice call protocol is required, but currently, there is no voice call setting signaling employing the OTP authentication yet.